feat(auth): share provider sign-in flows across clients - #12965

1. browse_code — Review these two selected files for Effect Service Conventions only: apps/server/src/provider/Layers/ProviderAuthService.ts and apps/server/src/provider/ProviderAuthFlow.ts at current PR head. Check namespace imports, Effect dependency acquisition, service construction conventions, runtime boundaries, error conventions, and whether focused tests cover newly introduced shared-binding concurrency/invalidation and ProviderAuthFlow behavior. Return only concrete violations introduced in these files, with exact lines and supporting context. Do not treat callback strategies or immutable config as service injection.

💭 Evaluating code changes I need to be cautious about any changes to imports in existing code. The only modification is to the ProviderAuth import, while others remain untouched. I should examine the full diff, particularly looking for any additions related to failures. It seems that line 60 is likely affected by the filtering addition of affectedIds. I wonder if the tests sufficiently cover this backend behavior change or if I'll need to inspect them more closely.

2. browse_code — apps/server/src/provider/Layers/ProviderAuthService.test.ts

💭 Checking test structure I'm considering tests that cover a specific feature. There's a convention in place, but I’m not sure if that has resulted in any findings. The request asks for "All clear," but the structured format seems to conflict with that. I realize I need to have complete check fields but can't provide an exact response for each line. Maybe it’s possible to title or summarize as "All clear"? I'll focus on ensuring there are no comments in the response.